Suffering is a side effect of higher development.

"Suffering is a side effect of higher development. We cannot avoid it in attaining insight. Human beings will one day say to themselves: 'I am grateful for the joy the world gives me, but if I had to face the choice of keeping my joys or my sufferings, I would want to keep my sufferings for the sake of gaining insight.' Every suffering presents itself after a certain time as something we cannot do without, because we have to grasp it as part of the development contained within evolution. There is no development without suffering, just as there is no triangle without angles. When unison with Christ is attained, we will see that all the preceding sufferings were necessary preconditions for this unison. In order for the union with Christ to be, suffering must be; it is an absolute factor in development.
     By overcoming egotism, human beings get over the mood of depression and feeling lamed or paralyzed. In this phenomenon we can see something that is good: strength out of insufficiency or inadequacy. Thank God that I am encouraged by an inadequate deed--that is, by its failure--to further action! Human striving is not a vague matter of luck. Only those whose free will turns away from the destiny of the human being remain unredeemed. In the synthesis of the world process, suffering is a factor."

--Rudolf Steiner, April 21, 1909. In The Spiritual Hierarchies and the Physical World, 2008 edition, p. 147